I suppose the best way to do it now is with a ThreadLocal in your listener.
The future 5.3.0 release will improve this a lot, CacheEntryCreatedEvent will have a getValue() method and CacheEntryModifiedEvent will have a isCreated() method: https://github.com/infinispan/infinispan/commit/1aa2554e1c5ea46318402975de946f2e9ea44442#diff-22
Well, that doesn't help me now as I'm stuck using whatever comes bundled with JBoss 7.X. I guess I'll have to wait.
Thanks for the reply.